Fair, M. L., & Williams, E. W. (1959). Economics of transportation. Harper.
Dyfyniad Arddull ChicagoFair, Marvine L., and Earnest W. Williams. Economics of Transportation. New York: Harper, 1959.
Dyfyniad MLAFair, Marvine L., and Earnest W. Williams. Economics of Transportation. Harper, 1959.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.